Star question.... Organic or Metallic? Binder?

[braddsn]

Ok so, another newbie question..... I have read many star comp formulas, and I see that there are "organic fuel" and "metallic fuel" formulas. From what I can gather, the metallic formulas are maybe a little more brilliant???? I will be rolling my stars in a roller, so for you folks that roll your stars, do you use the organic or metallic formulas, and why? (Assuming that you can obtain all chemicals involved in both processes.)

 

And furthermore, and I know this may be a stupid question... but as far as binders/solvents are concerned, what are most of you using? It seems like dextrin/water would be easier to work with then say parlon/acetone... however when reading the star formula charts, some formulas call for dextrin, some call for red gum, etc etc. So suppose I get all set up to roll stars... wouldn't I want to pick 1 binder and stick with that?? The binder part is still a little confusing to me.

 

Thanks in advance!

 

-Brad

Edited August 11, 2014 by braddsn

[MrB]

Binders aren't "just" binders. Ideally they would be, of course, since you could mix and match as you please.

Unless you feel a bit like experimenting, sticking to known good formulas sort of forces you to use what ever binder they are supposedly using.

For rolling, it doesn't really matter what binders you use, it just amounts to different amounts of mess. Your going to want to clean it all out between batches of different color anyway, so thats quite all right.

B!

[pyrokid]

I prefer dextrin. It is simple and cheap. I think you'd have quite a hard time rolling with acetone anyway.

 

I generally choose between metallic and organic depending on what effect I'm trying to produce. Some metallic colors are very bright and will wash out the color palette of spectators. Sometimes this is a good thing, sometimes not.

 

The Japanese masters use the differences between metallic and organic formulas in their displays, it's fantastic.

[TYRONEEZEKIEL]

Here are some quick guidelines regarding your questions

 

Organic fuels(comps that don't have metal powder) have a more saturated color but are dim and are easily overpowered by a metallic fueled star

 

Metallic fuels(comps that use metal powder) increase the brightness and brilliance of the star, but may have a tendency to wash it out and give it a white hue

 

In general most stars are metallic except blue. Blue is almost always organic as it is the most difficult color to produce. Naturally there are exceptions to all of these guidelines above.

 

Now for binders, dextrin/water is the easiest to roll and clean up. It is also the most common binder by far. However it makes unnecessary smoke in the star and in some cases is undesired.

 

Red gum/alcohol binding is sometimes employed when dex/water won't work. For instance red gum is a much better fuel and helps maintain the color purity. Also for hygroscopic chems like Strontium Nitrate, using a water bound star will turn it to mush and is difficult to dry.

 

Phenolic/hexamine binding is usually reserved for large comets. It binds super hard and in fact requires a curing time in 140° temperature. This keeps them from blowing apart under lift.

[TYRONEEZEKIEL]

Acetone/Parlon binding is only used for cut stars. In any other situation I'm sure it would make an extreme mess. The plus side is the stars dry in a few hours instead of a few days.

 

In general. Stick with dextrin bound stars. It is the cheapest binding material by a long shot. It gets rock hard and is universal among all star making procedures

[Bcorso85]

Others have pretty much covered it. However I want to add that some binders also act as chlorine donors. Adding chlorine to lets say strontium stars enrich the color. ..Creating strontium chloride. Dextrin works fine in most basic star formulas. I love glitter and charcoal stars with a basic color star core. Here....dextrin is best. Red gum in color stars acts like a fuel, as mentioned. Parlon stars become much harder to light. Because parlon is chlorinated rubber...acetone is the best solvent to dissolve it. Parlone can also be used as above...but can coat uncoated magnesium when used in go getters. I like simplicity. By using rubbing alcohol to roll my stars I get a quicker drying time, cut surface tension, and the little water in it activates the dextrin. Hexamine I like in a simple blue formula. Binds...fuels...and adds chlorine. 57% I believe.

[Mumbles]

Hexamine isn't really a binder and has exactly 0% chlorine by mass.

 

Most people will use parlon, red gum, etc for chlorine donor and fuel respectively, and dextrin as the binder. There seems to be some delusion that just because you can dissolve them, that you should. I assure you that just because a formula contains red gum or parlon that dextrin still works just fine. There are a few niche uses that benefit from non-aqueous binding, as have already been mentioned, but a majority of serious hobbyists use water for 95+% of applications.

[schroedinger]

Hexamine doesn't add any chlorine!

 

The solvent and binder always depends kn the wanted result. Some system are better for some purposes then other.

Water activated binders are the ones most often used. Where destrix is used quite often, as it is very cheap, but also gum arabicum, rice starch and cmc are water based, and can most times be used.

 

Alcohol based binders are most often red gum or shellack (with methanol also NC), they dry faster then water bound stars, and can give some real superb stars 0. (Also they allow the use of hygroscopic substances like strontium nitrate, if they get dried before use.) These are for example used in organic stars which use the binder also as a fuel.

Also they can be used to surpress reaktions which could occur in water based system, like aluminium/nitrate, but most times boric acid gets used here.

 

The third big group are the "organic solvent" (i know alcohols are also organic solvents), like Aceton or Toluene. These are most times used because the binder requires them, like parlon which requires e.g. aceton or NC which requires methanol, aceton ... . For example parlon bound stars are known to give some superior colors, or NC which is required in most DE formulas

 

Also there is a whole lot of other solvents which can be used in some applications.

 

So you see there is no "the solvent/binder"

Edited August 12, 2014 by schroedinger

[Mumbles]

Red gum is not activated by water. NC, if it's any good, is not activated by methanol.

[braddsn]

Wow guys that is a ton of great info! Thanks! I for one like simplicity. I want to focus on simplicity and safety as I learn the trade. So from what I gather, would it be safe to say that for the first couple years, just choose star formulas that use dextrin/water as binder.... then maybe experiment later as I gain experience? I have just today started gathering supplies to build my star roller! Ball mill also on the way!

[schroedinger]

Red gum is not activated by water. NC, if it's any good, is not activated by methanol.

Your right of course gum arabicum was meant.

But maybe you should go and do some research about methnol and nc again.

 

NC is graded in three classes, defined by nitrogen content. Only a-class nc 10.7-11.3 % is soluble in ethanol, but methanol has a special position as it also can dissolve higher nitrogen content.

If you look into the data sheet of nc from e.g, dow you will find methanol listed under the category activators or real solvents.

 

Also i can assure that it works perfect from personal experience that it works perfect